Add basic unit tests

pom.xml

@@ -31,5 +31,13 @@
         </plugins>
     </build>
 
+    <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.12</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
 
 </project>

src/test/java/cz/adamh/utils/NativeUtilsTest.java

@@ -0,0 +1,29 @@
+package cz.adamh.utils;
+
+import java.io.FileNotFoundException;
+import java.io.IOException;
+
+import org.junit.Test;
+
+public class NativeUtilsTest {
+
+    @Test(expected=IllegalArgumentException.class)
+    public void testLoadLibraryIllegalPath() throws IOException {
+        NativeUtils.loadLibraryFromJar("libtest.so");
+    }
+
+    @Test(expected=IllegalArgumentException.class)
+    public void testLoadLibraryIllegalPrefix() throws IOException {
+        NativeUtils.loadLibraryFromJar("/l");
+    }
+
+    @Test(expected= FileNotFoundException.class)
+    public void testLoadLibraryNonExistentPath() throws IOException {
+        NativeUtils.loadLibraryFromJar("/libtest.so");
+    }
+
+    @Test(expected=NullPointerException.class)
+    public void testLoadLibraryNullPath() throws IOException {
+        NativeUtils.loadLibraryFromJar(null);
+    }
+}